So-called sandwich components are increasingly being used as structural elements in aircraft production. In this case, a core is covered with a fibre material which is impregnated with a matrix material and thus connected to the core. For example, a foam is used as a core material, it being possible to provide the core with additional reinforcements in order to increase the rigidity. In the case of reinforced cores in particular, thermally induced crack formation can occur in the core during the production process of the sandwich component, which is exposed to an increased temperature in order to harden the matrix material. In this case, there is the risk that, once formed, a crack will spread through the entire core and thus weaken the structure of the sandwich component considerably. The presence and also the development of an incipient crack in the core can only be detected with difficulty. This is made more difficult by the fact that the crack development is a time-driven process, in other words, the structural-mechanical properties of a sandwich component having an incipient crack in the core of the component may deteriorate considerably and unpredictably over time. This may result in damage to or even disintegration of the structural element formed as a sandwich component. This is obviously to be avoided.